Telegraphic repeater



(No Model.) 2 Sheets-Sheet 1.

W. E. ATHEAR'N. l

TBLEGRAPHIG REPEATER.

Patented Oct. 2, .1883.

07%Q/LMAC:

(No Model.) 2 Sheets-Sheet 2.,

W. E. ATHEARN.

TBLEGRAPHIG REPBATER. No. 286,107. Patented Oct. 2, 1883.

SZLQZOH? Iii UNITED STATES PATENT EErcE,

TILLIAM E. ATHEARN, OF PHILADELPHIA, PENNSYLVANIA."

- TELL-:GRAPHIC REPEATER.

SPEGIFICATION forming part of Letters Patent No. 286,107', dated October 2, 1883.

Application filed October Q5, 1882. (No mcdelJ To @ZZ whom it may concern,.-

Be it known that I, WILLIAM E. ATHEARN, a citizen of the United States, residing in Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Automatic Telegraphic Repeaters, of which the following is a specification.

My invention relates to a certain class of telegraphic apparatus known as automatic repeaters or translatorsf7 the function of which is to receive the signals which have been telegraphically transmitted over a line from a distant station, to retransmit the said signals over a second line, and also to perform the reverse operation of retransmitting and repeating similar signals from the second line intothe iirst without the intervention of an attendant. rlhe apparatus hitherto in use for this purpose has been designed for the reception and retransmission of telegraphic signals formed by alternately interrupting and restoring an electric current of unchanged polarity, but is not adapted to the requirements of telegraphic systems in which the signals are formed by transmitting electric currents of a1- ternating polarity.

The object of my invention is to reccivevand retransmit in either direction telegraphie signals of alternating polarity; and to this end I make use of a pole-changing or alternating current-transmitter, which is adapted to be operated by the agency of currents of like character received upon one line and to retransmit corresponding currents upon another line 5 and it also comprises an automatic switch, whereby the receiving and transmitting device may be automatically interchanged between one line and the other, so that retransmission in either direction may be effected without the aid of an attendant.

rlhe subject-matter claimed as new will be hereinafter more speciiicall y described and pointed out.

In the accompanying drawings, Figure l is a theoretical plan illustrating my invention, in which I have shown the apparatus at an intermediate or repeating station in connection with thesending and receiving apparatus of two terminal stations, the latter being indicated in outline. rlhe intermediate station is designated as station B, and the terminals as stations A and C, respectively. Fig. 2 represents the same apparatus in the position which it assumes during the act of transmitting from station A to station C.

The apparatus at station A comprises a key, K, the lever of `which may be connected to the line L at pleasure by means of a switch orbutton, w. The front contact of the key K is connected with the positive pole of a nain battery, e, and the rear contact with the negative pole of another similar battery, f, the opposite poles of said batteries being united with each other and with the earth at g. It will be understood, therefore, that when the key K is manipulated by the operator in the usual manner of transmitting arbitrary tclegraphic signals alternate positive and negative currents will be transmitted through the switch w over the line L to station B, the switch being in contact with m. When signals are to be received over the line L from station B, the switch w is removed from the contact x and placed upon the contact The signals will then pass through the receiving-instrument R, which consists of an electro-magnet provided with a polarized armature of well-known construction, and thence to the earth at g.

The several parts of the apparatus at station C are constructed and arranged in the saine manner as at station A, and are designated in the drawings by similar letters of reference having the numeral l aliiXed thereto. Thus K represents the key, R the receivinginstrument, and so on.

rlhe apparatus at the intermediate station, B, comprises a pole-changing transmitter, T, consisting, essentially, of an electro-magnet having a polarized armature which is caused to oscillate to and fro between two contact points or stops, o and c', which latter are respectively connected to the unlike or opposite poles of two batteries or other suitable sources of electricity, E and E.

The automatic switch or circuit -ehanger comprises a horizontal metallic lever, D, poised upon an axis, d, at the center of its length, and separated into two parts by insulating material at D. Beneath this lever, at equal distances from its axis, are placed two electromagnets, C and C', which act upon correspond- IOO ing soft-iron armatures placed above and o pposite their respective poles, and attached to the automatic switch D in a well-known manner, as shown inthe figure. Two insulated springs, d/ and d2, are mounted upon theupper 'side'of the respective arms of thc automatic a contact, c, formed upon the end of the automatic switch D. Vhen this end of the lever is depressed, the spring a remains in contact-with the stop c, and atthe same instant is separated from the iixed stop b. `When the same end of the automatic switch is raised, the spring a is separated from Ythc contact c. A similar device is placed at the opposite end ot' the automatic switch D, as shown in the drawings, the spring being designated as c', the iixed stop as b, and so on. rlhe springs u, and a also make alternate contact with the lined stops 'u and e at each extremity of the to-and-fro movement of the automatic switch D, which switch is normally maintained in its intermediate position, when no current is passing, by the action of the springs (l, a.

The main-line wire L coming from station A divides at the point l into two branches, the branch 2 being connected to the left-hand portion of the automatic switch D and the branch 5 to the contact-springt?. A non-polarized or neutral relay, M, of well -known construction, is placed in the branch 2, and I prefer, also, for reasons hereinafter set forth, to include in tlie main line L a receiving-instrument, S, provided with a polarized armature responding to changesin the polarity in the actuating-current. wire, L', extending from station B to station C, in like manner proceeds from the point of union at 7 of two branches, one extending from the contact-spring lL andthe other from the correspondlng arm of the automatic switch D. The stops e and c are connected by cenductors 3 3 with one terminal of the electromagnet of the pole-changing transmitter T, and the other terminal thereof is connected with the earth by the conductor 4.

The electro-magnets C and C, which alter nately actuate the automatic switch D and its attachments, are themselves actuated by the local battery Z, which is connected with them and with the neutral relays upon each side of the apparatus in the following manner: The armature-levers of the neutral relays M and M are electrically united by a conductor, 8, and the rear contact-stops of these relays are in like manner united by the conductor 9. The terminals of the electro-magnets C and C are attached by means of short branches to the rlhe other main-linev conductors S and 9, respectively, as shown in the igure, and a local battery, Z,`is included in the wire 9l at a point between the point of attachment of the terminals of the electromagnets. By inspecting this organization of circuits it will be observed that when the armature of the neutral relay M falls on its back contact, the current ofthe local battery l will be diverted from the electro-magnet C by way ot' the shunt formed by its armature, and hence the latter will be rendered inoperative, while the other electro-magnet, C, will remainin action. rthis-operation will be reversed as to the electro-magnets C and C' by the breaking ofthe shunt at M and the closing of the shunt at M. In Fig. 1 the various parts are represented inthe position which they respectively occupy when both lines are at rest.

If we suppose a communication is to be transmitted from station A over the line L to station B, and at lthe same time automatically retransmitted from station B over the line L to the station C, the operation o' the apparatus will be as follows: By changing the switch w (see Fig. 2) from the contact stop x to the contact-stop x, and by manipulating the key K at station A in a wellknown manner, alternate positive and negative currents of equal strength, constituting -tclegraphic signals, are transmitted over the line L from the batteries c and j'. These alternate currents, reaching the point l at station B, pass through the coils ef the neutral relay M, and thence by wire 2 to contact c, contactspring c, stop I), and wire 12 to the earth at Gr.v rlhe neutral relay M, responding equally to currents of either polarity, now holds its armature away from its back contact. This interruption of the shunt renders the local electro-magnet C active, thereby pulling down and holding the left-hand end of the automatic switch D. By this means the connection ol' the wire 2 with the earth is interrupted and a new contact is established between the wires 2 and 3 at the stop y, and also ybetween the spring d2 andthe stop rlhe polarized armature ofthe polechan ging transmitter T now responds to the alternate positive and negative currents transmitted through its coils by way of the wire 3, and is thus brought into alternate contact with the stops e and e, which constitute the terminals, respectively, of the positive and negative batteries E and E. The

armature of the electro-magnetic transmitter T thus forms a key, by means of which alternate positive and negative currents are sent through the connecting-wire 5, stop i, and wire 6 to the point 7, and thence over the line L to station C, and iinally through the receiving-instrument It at that station to the earth at g. The incoming current at station B Apreferably passes through the coils of asounder or other receiving-instrument, S, provided with a polarized armature and placed in the wire.L, whereby the attendant may ascertain at any time whether or not communi- IOO IIO

cations are passing. Vh'en the transmission from station A has been completed,thc switch or button w at that station is turned on the point x', thus placing the line L to ground through the receiving-instrument Rand leaving no current on theline. lt', now, the operator at station C should desire to transmit a communication in the opposite direction to station A, he rst changes the switch w so as to place the keyK in connection with the line L. The initial current transmitted over the line, on arriving at the point 7, passes through the neutral relay M' and by the wire l 0 to the contact c and the contact-spring c', and thence through the stop and wire ll. to the earth. 'It cannot pass from thepoint 7 through the branch (l,for the reason that the spring (lil is held in an intern'icdiate position by the position ol' the automatic switch l), thus leaving the circuit disconnected at that point. The passage of the initial current through the neutral relay ll'L interrupts the shunt around the electro-magnet C in the manner hereinbefore explained, and thus brings the latter into action, depressing its own end of the automatic switch D and elevating` the opposite end, the effect ot' which is to break the eenneetion between the spring a and stop'b, and to put the line L to earth through the electro-magnet of the pole-changing transmitter T, and also at the same time to connect the armature of the transmitter T with the line L by bringing the spring d into contact with the stop v3. The position of the several parts is now precisely the same as in the former case, except that they are arranged to operate inthe reverse direction. Thus it will be understood that the transmission of the initial electrical impulse l'romeither terminal station by its automatic action through the neutral relay upon the circuit-changing mechanism establishes the necessary conditions to insure the linbefore set forthfof a polarized armature, an

electro-magnet for actuating said armature by the influence of alternate positive and negative currents traversing` its coils, a line-wire electrically connected with said ari'nature and extending to earth at a distant terminal station, and a positive and a negative source of electricity with which said armature is alternately placed in connection when moved to and fro by alternating currents traversing the coils of its actuating electro-magnet.

2. The combination, substantially as hereinbefore'set forth, of a polarized armature, an electro-magnet for actuating said armature by the influence of alternate positive and negative currents traversing its coils, a line-wire extending to earth at a distant terminal station temporarily connected with said armaA ture, a positive and a negati vc source of electricity with which said armature is alternately placed in connection whenv moved to and fro by alternating currents traversing the coils of its actuating electro-magnet, and means for maintaining said armature out of connection with said main line when no current is traversing the coils of its electro-magnet.

f fl. The combination, substantially as here inbel'orc set forth, ofiapelarized armature, an electro-magnet for actuating said armature by the influence ol' alternate iositive and nevativc currents traversing its coils, two independent line-wires extending to earth at dit'- ferent termina-l. stations, an automatic switch for electrically connecting said armature with one or the other of said line-wires, and a positive and a negative source of electricity with which said polarized armature is alternately placed in connection when moved to and fro by alternating currents traversing the coils of its actuating electro-magnet.

4t. The combination, substantially as hereinbe fore set forth, of a polarized armature, an electro-magnet for actuating said armature by the inuence of alternating positive and negative currents traversing its coils, two independent line-wires extending to earth at different terminal stations, an automatic switch acting through the influence of an incoming current traversing either line-wire Vto place that line-wire in electric connection with the earth through the coils of said electro-magnet, and to place the other line-wire in electrical connection with said polarized armature, and a positive and a negative source of electricity with which said polarized armature is alternately placed in connection.

5. The combination, substantially as hereinbefore set forth, of a positive and anegative source of electricity, a pole-changing transmitter for placing said sources of electricity alternately in connection with an automatic switch, two independent line-wires extending to earth at different terminal. stations, two independent electro-magnets acting upon said switch, to thereby place the pole-changing transmitter in connection with one or the other `of said lines respectively, and two relays for IOO IIO

different terminal stations, each line-wire proceeding from the junction of two branches, one of which branches extends from one -of said contact-springs and the other normallyy from the earth, and two electro-magnets, one being included in each of said earth-branches, and means, substantially such as described,

- for placing the one or the other of said contact-springs in connection with the corresponding' contact-point through the instrumentality of saidelec,tromagnets. i

7. The, combination, substantially as hereiubefore set forth, of a pole-changing trans! mitter, two independent line-wiresv extending to different terlninal stations, an automatic switch for alternately placing said transmitter i n connection with one or the other'ofsaidlines,

two electro-magnets for alternately reversing` the position of said automatic switch, a local battery aud neutral relays actuated alternately by the incoming; currentsfroin said line-wires, respectively, for controlling the action of said -local battery upon the electro-magnets by which the automatic switch is reversed.

both said lines are normally connected to the earth and disconnected from the transmitter, but either of said lines may be transferred from the earth to the transmitter, while the other line is simultaneously transferred from the earth to the electro-magnet which actuates said transmitter.

In testimony whereof I have hereunto subscribed my name this 21st day of October, A. D. i882.

XVM. E. ATHEARN.

lVitnesses:

E. I-I. BAILEY, BENJ. R'BRAIsTED. 

